For the second year in a row, Google's parent company Alphabet will oppose a shareholder plan that would commit the business to evaluate and disclose whether it has a pay gap between female and male employees.

Arjuna Capital, the investment firm advancing the proposal on behalf of stockholders, told BuzzFeed News that Alphabet sent them a statement of opposition ahead of the company's annual shareholders meeting this summer. Google declined to comment on the plan.

Last week, as part of an ongoing investigation against Google, an official with the Department of Labor said the agency "found systemic compensation disparities pretty much across the entire workforce.”

Natasha Lamb, Arjuna's director of shareholder engagement, said there is a difference between paying lip service to gender pay equity and actually being transparent about it.

"They have been unwilling to do that," Lamb said. "That's unsettling given how proactive their tech peers have been, and also given what we just saw with the Department of Labor accusing them of extreme gender pay disparity. It makes one question what's really going on here, when there isn't full transparency and accountability."

On Tuesday, Google's vice president of people operations, Eileen Naughton, said in a blog post that "we were quite surprised" by the Labor Department's accusations. "We were taken aback by this assertion, which came without any supporting data or methodology," Naughton said. She went on to explain Google's pay equity auditing policies, which she described as scientific and rigorous. The company claims that "there is no gender pay gap at Google."

But Arjuna Capital says the gender pay gap and employee compensation data in the US have been unfairly hidden from public view for decades, and wants companies to do more to increase their accountability. "This is not only the right thing to do from a social justice standpoint and a broad economic standpoint, it's simply good business for companies to be paying women a fair wage and to attract and retain top talent," Lamb said.

Like several other big tech companies, Google releases annual diversity reports, sketching the ethnic and gender breakdown of their workforce. In 2015, detailed in Google's most recent report, Google's overall staff was 31% women and 69% men. 59% of Googlers were white, 3% were Hispanic, and 2% were black. "We’re still not where we want to be when it comes to diversity, but last year, we made progress in our efforts to build a more diverse Google," the company said.

Google's diversity reports, however, do not include gender pay data; the company shares how many women work there, but not how they are paid relative to men working in similar roles.

Last year, Arjuna led a campaign to pressure nine major tech companies— including Apple, Amazon, Intel, and Microsoft — to release their gender pay data. Of the nine targeted companies, only two have not disclosed their data: Alphabet and Facebook, although both companies claim to maintain gender pay equity.

Apple's study, for example, found that women there made 99.6 cents for every $1 men earned; Microsoft said its female employees earned 99.8 cents for every dollar men took in; and Amazon found women's compensation to be 99.9% of men's, in equivalent roles. But even with these seemingly slight compensation discrepancies, annual diversity reports for many of tech's biggest companies continue to reveal lopsided workforces, with higher-paying and leadership positions dominated by men.

Facebook did not respond to a request for comment.

According to Alphabet's 2016 proxy statement, the board of directors told stockholders that they did not believe a proposal to disclose a possible gender pay gap "would enhance Alphabet’s existing commitment to fostering a fair and inclusive culture." The board cited Google's existing diversity reports and Google's pay equity audits as safeguards against discrimination.

The Department of Labor's lawsuit against Google, announced in January, stemmed from the company's alleged failure to provide the government with employee compensation data. But Google maintains that the government's records requests are overbroad and would reveal sensitive information about their employees.

Hamza Shaban is a technology policy reporter for BuzzFeed News and is based in Washington, DC.